What Is a Synthesizer? Types of Synths Explained

Here you’ll learn what a synthesizer is, its main parts, how it works, and the most common types of synthesizers, explained in a simple and beginner-friendly way.

1. What Is a Synthesizer and How Does It Work?

A synthesizer is an electronic instrument capable of generating sounds from scratch. It does this by electronically creating sound waves and shaping them using different tools.

Synthesizers can create completely original sounds or mimic other instruments through sound design techniques.

In section 2, we’ll take a look at the main parts of a synthesizer.

1.1 How Does a Synthesizer Work?

Here’s how synthesizers work:

The synthesizer generates a basic signal, a waveform, usually selected from common types like sine, sawtooth, square, or triangle waves.

From there, more waves can be layered using additional oscillators. The waveform can also be shaped or reduced using filtering (subtractive synthesis).

These are the basic types of synthesis, but many more elements are added to further shape and enhance the sound, such as envelopes, modulators, or effects.

This is the Sylenth1 VST synthesizer by Lennar Digital

Nowadays, with the rise of software-based or VST synthesizers, wavetable synthesis has become especially popular, like the type used in Serum.

With this kind of synthesis, instead of starting from basic waveforms, you can digitally sculpt the waveform from the beginning, drawing it in visually. This gives much more flexibility and irregularity in the sound’s foundation.

2. What Are the Main Parts of a Synthesizer?

Most synthesizers share these 4 basic components: Oscillators, Filters, Envelopes, and LFOs.

2.1 Oscillators (OSC):

Oscillators generate the initial sound waves. They are the origin of the sound.

The main basic waveforms are sine, sawtooth, square, and triangle.

Some oscillators also include noise waveforms, which aren’t particularly interesting on their own but can create unique textures when subtly layered with other oscillators.

2.2 Filters (FILTER):

Filters are used to remove or emphasize specific frequencies.

For example, you can use filters to make a sound feel softer or brighter.

2.3 Envelope (ENVELOPE or ADSR):

An envelope controls how the sound evolves over time using four parameters: Attack, Decay, Sustain, and Release (ADSR).

Let’s break them down:

Attack: how long it takes the sound to reach maximum volume.
Decay: how quickly it decreases after the attack, down to the sustain level.
Sustain: the level held while the key is pressed.
Release: how long it takes for the sound to fade after the key is released.

2.4 LFO (Low Frequency Oscillator):

An LFO is a much slower oscillator. Instead of producing sound, its waveforms are used to modulate or alter other parameters.

These modulations could include filter changes, volume variations like tremolo, or affecting the main oscillators, typically in a cyclic way.

Most LFOs allow you to set the waveform shape, modulation depth, speed (rate), and more.

2.5 Other Elements

Other common components include:

Amplifiers (which control the output volume).
Effects modules to further enrich the sound.
And the arpeggiator, often included to create melodic or rhythmic patterns, though not all synths have one.

3. What Types of Synthesizers Are There?

Synthesizers can be categorized in several ways. In this guide, we’ll break them down into: analog, digital, hybrid, modular, and virtual (VST/software).
They can also be classified by synthesis type (click here to explore that).

Back in the mid-20th century, synthesizers started out as analog machines using electrical impulses to generate sound waves through oscillators. As technology advanced, hybrid versions emerged, eventually leading to today’s fully digital, software-based VST synthesizers, now the most commonly used.

Let’s briefly explore each type:

3.1 Analog

They work through electric circuits, generating sound from analog voltages and oscillators. They’re known for their warm, organic, and sometimes unpredictable sound.

Analog Synthesizer: Moog Subsequent 37

3.2 Digital

Digital synthesizers are physical instruments without analog oscillators. Instead, they use processors and synthesis algorithms to create and shape sounds digitally. They offer more precision, multiple synthesis types, and advanced features in a compact format.

Digital Synthesizer: Access Virus TI

3.3 Hybrid

These combine both digital and analog components. Most often, they use digital oscillators with analog filters or other analog stages.

Hybrid Synthesizer: Sequential Pro 3

3.4 Modular

Modular synths are made up of separate components (oscillators, filters, LFOs, etc.) that must be connected manually with patch cables. This offers ultimate flexibility, but requires advanced knowledge.

Modular Synthesizer: Make Noise Shared System

3.5 Virtual / VST / Software

These are software-based instruments that simulate the functionality of a real synthesizer. They run on computers or mobile devices, usually as plugins inside a DAW (Digital Audio Workstation), although some work standalone.

VST Synthesizer: Xfer Serum

They’re perfect for modern production. Check out this list of top recommended VST synths.

Frequently Asked Questions – FAQ:

What Can You Do With a Synthesizer?

A synthesizer lets you generate sounds from scratch, from shaping the raw waveforms to creating the desired tone and texture. They’re widely used in modern music, film, video games, and all kinds of audiovisual content. You can craft entirely unique sounds or imitate existing ones.

What’s the Difference Between a Keyboard and a Synthesizer?

A synthesizer is focused on sound synthesis, generating and modifying waveforms. Some physical synthesizers include a keyboard, but others don’t and are used with MIDI keyboards, just like software synthesizers.
A keyboard, on the other hand, could simply be a MIDI controller (with no sound engine), or it might come with built-in sounds but no synthesis capabilities.

How Many Types of Synthesizers Are There?

Synthesizers are usually divided into 4 main types: analog, modular, digital, and virtual (VST). There’s also a hybrid category combining analog and digital elements. You can read more about them in the article.